Cutting or machining tools for rotary drive cutters may be used to drill holes and cut shapes in different types of metals and woods. However, cutting tools may not always leave a clean cut and tend to leave a lot of debris, such as chips and dust, on the top and bottom of the work piece. Further, due to the low compression cut, the cutting tools cause a lot of movement of the work piece which also results in a rougher cut and surface chips on the work piece. As can be seen, there is a need for a cutting tool that provides less movement and less chipping, particularly for wood and composite materials.
Cutting tools that machine a work piece by utilizing cutting edges that rotate around the center axis of a basically cylindrical tool have generally been produced in one of two types.
One type is made entirely of one material such as high speed steel or tungsten carbide and having one or more helical or spiral cutting edges where each cutting edge is made up of one continuous edge and all the various cutting geometry such as inclination angle (IA), rake angle (RA), and clearance angle (CA) are continuous throughout the length of the cutting edge. Also due to the nature of a helix or spiral the rake face of these tools would have no planer/flat surfaces.
The other method of design and manufacture of cutting tools involves having an essentially cylindrical tool body that is made of a steel alloy, typically carbon steel, with cutting plates or tips (teeth) attached to the body by brazing, soldering, adhesive bonding, etc. In the case of the invention the cutting tip material is an ultra-hard material, Polycrystalline Diamond (PCD).
In these types of cutting tools there are four basic cutting geometry angles that affect the performance of the tool. 1) the angle of the rake face (RA), and 2) the flank relief or radial clearance angle (CA), 3) RA and CA angles combine to create a wedge angle (WA) which determines the relative edge sharpness, and the fourth angle between the cutting edge of the tip and the axial centerline of the tool rotation. This is referred to as inclination angle (IA) or “shear” angle. This inclination angle (IA) is zero or the cutting edge is parallel to the centerline of axial rotation then it is perpendicular to the direction of motion of the tip as it progresses through the cut.